From my vantage point at the top of a lush hillside, I cast my eyes across the thick carpet of grey ash below, strewn with charred tree stumps and boulders the size of cars – a hellish landscape created 15 years ago by the catastrophic eruption of the Soufrière Hills volcano on the Caribbean island and British Overseas Territory of Montserrat.

Unchanged since superheated rocks and ash tore down the flanks of the volcano on 25 June 1997, the scene is sadly symbolic of the fate of many Montserratians since – neglected and seemingly forgotten both by their own government and the authorities in London. Nineteen people were killed on the day the mountain laid waste to the island's capital and its airport.

The question remains as to why those displaced by the volcano were forced to live for many months in subhuman shelters in the north of the island, and why many are still living in temporary accommodation today – a few still on the island, but the vast majority in a state of involuntary exile in Britain, the US and elsewhere in the Caribbean.

Consider Anna Robinson. Blind and in her mid-60s at the time, she lost her husband Peter to the volcano. The inquest into the deaths of those who died in the eruption found that "the failure of the authorities both local and British to provide alternative lands in the safe area for farmers displaced" was a contributory factor. Anna, meanwhile, was moved to Brades shelter on the northern part of the island, where she lived for 18 months. She may not have been able to see the seepage from a blocked toilet across the corridor that trickled through her room, but she could smell it and hear the clouds of flies.

Now 80, Anna lives in a room in London. Along with fellow Montserratians of similar age, she prays to return to Montserrat to live out the rest of her days "even if it means that I must live in a house that is so small that my feet stick out".

Given the lack of investment on the island over the past 15 years, and the extent of its neglect, she is all but certain to die with her prayers unanswered.

I believe that Anna, and the 4,000 other Montserratians who like her remain in exile, deserve some very belated justice. It is true to say that though we call them "natural", most disasters are manmade – it is a lack of preparedness and response that leads to human suffering and loss of life.

I have tried repeatedly over the years to extract from the authorities both in Montserrat and in London explanations (and documentation that I know to exist) to understand why the response to it was – and remains – so pitifully inadequate. But my FOI requests have been rejected, my letters to prime ministers ignored.

Fifteen years after our island and its economy were devastated and its people scattered far and wide, a thorough and public investigation to determine exactly what went wrong and what needs to be fixed is almost criminally overdue.